2011 blackout caused by human error, poor planning

The massive black­out in South­ern Cali­for­nia in Septem­ber 2011 began with a loss of a trans­mis­sion line in Ari­zona and rippled quickly west due to a series of hu­man er­rors and in­stances of “in­ad­equate plan­ning” by util­ity agen­cies, ac­cord­ing to a re­port is­sued by the Fed­er­al En­ergy Reg­u­lat­ory Com­mis­sion and the North Amer­ic­an Elec­tric Re­li­ab­il­ity Corp.